Blow molding operations utilized in the manufacture of plastic containers, or bottles, typically include the formation of flash along a mold parting line in one or more areas of the blown container, such as, the shoulder, neck, finish, and handle areas. Thus, a conventional operation includes discharging the containers from blow molds onto a wheel discharge takeaway conveyor which transports the containers to a trimming machine. The trimming machines sever the flash from the containers and may also be utilized to trim the end face of each finish to provide a scaling surface capable of engaging a closure in a leak-free manner.
Trimming machines typically are capable of receiving and trimming multiple containers at a time. Thus, sets of containers are sequentially input into the trimming machine in a start/stop manner. Each set may include, for example, four containers. So-called index bucket chains, or receivers, are typically utilized to input, or index, containers into the trimming machine. The index bucket chain includes a plurality of end-to-end configured buckets which are each capable of holding one container to be input into the trimming machine.
A transfer mechanism is required to transfer the containers from the takeaway conveyor to the index bucket chain of the trimmer. The takeaway conveyor typically operates at a continuous speed. Thus, the transfer mechanism must be precisely synchronized with the movements of the containers on the continuously operating takeaway conveyor and with the movements of the sequentially operating index bucket chain in order to simultaneously transfer multiple containers from the takeaway conveyor to the index bucket chain in a repeated manner. For example, containers may be transferred four at a time from the takeaway conveyor to the index bucket chain and into the trimming machine.
Known transfer mechanisms utilized to transfer containers into trimming machines utilize vacuum pick and place mechanisms. Such mechanisms include vacuum suction heads which physically contact and lift containers from the takeaway conveyor and mechanically position the containers into the trimmer or into the buckets of the index bucket chain of the trimmer. Examples of known vacuum pick and place mechanisms are disclosed in U.S. Pat. No. 4,614,018 issued to Krall, U.S. Pat. No. 5,681,597 issued to Aguilar et al., and U.S. Pat. Nos. 4,886,443 and 4,834,643 issued to Klinedinst et al.
Vacuum pick and place machines have relatively complicated structures and are relatively expensive to build and/or purchase. They require frequent maintenance and are prone to experiencing mechanical and pneumatic failures. The downtime of the pick and place machines can significantly reduce the overall rate of manufacture of containers. Thus, a more efficient and cost-effective transfer mechanism for transferring containers from a takeaway conveyor to an index bucket chain of a trimming machine is desired.
It is known to direct blasts of air at articles to deflect the articles in an intended direction. For example, the embodiment of FIG. 19 of U.S. Pat. No. 4,369,873 issued to Heuft discloses the use of air blasts to laterally deflect upstanding bottles on a conveyor into one of a pair of alternate paths. U.S. Pat. No. 5,322,152 issued to Tommila et al. discloses the use of air blasts to sort various recycled articles, such as upstanding bottles and cans. U.S. Pat. No. 5,135,101 issued to Dudley, U.S. Pat. No. 3,797,640 issued to Aidlin et al., U.S. Pat. No. 3,603,645 issued to Hardy, and U.S. Pat. No. 5,248,045 issued to Alvelda disclose other bottle handling apparatus which utilize blasts of air to accomplish various tasks. U.S. Pat. No. 2,851,146 issued to Sherrill, U.S. Pat. No. 4,214,663 issued to Schopp et al., U.S. Pat. No. 5,065,858 issued to Akam et al., U.S. Pat. No. 4,042,099 issued to Sterling, U.S. Pat. No. 3,329,469 issued to Stadelman and U.S. Pat. No. 3,398,823 issued to Hollenton disclose various mechanisms utilizing blasts of air to transfer non-bottle type of articles, such as cigarettes.
While various ones of the transfer mechanisms disclosed in the above referenced patents may function satisfactorily for their intended purposes under certain circumstances, there is a need for a mechanism and method for efficiently transferring blow-molded containers from a wheel discharge takeaway conveyor to an index bucket chain of a trimming apparatus. The transfer mechanism should have a relatively simple construction which requires a minimum of downtime, if any, and which is cost-effective to manufacture and/or purchase.